The major goals are: (a) to understand the dynamics of biosynthesis and release of luteinizing hormone (LH) and (b) to understand the regulation of LH synthesis and release. The specific goals for the next year are: (a) To further characterize "big LH" by additional biochemical and biological studies. The rat bioassay will be established to monitor the biological activity of different forms of LH. Additional pulse-chase studies will be conducted in the presence and absence of GnRH. Results will be analyzed both by gel filtration and SDS gel electrophoresis. (b) To determine if thyroid dysfunction affects LH biosynthesis in rats with intact ovaries. (c) To determine if thyroidectomy alters binding of GnRH to the AP. (d) To determine the effects of GnRH agonists on LH synthesis and release in rats subjected to estrogen therapy. (e) To determine the effect of GnRH on carbohydrate metabolism and the relationship of carbohydrate metabolism to LH biosynthesis.